We want tie comm cable to the conduit in our building .and some said it was not up to code.Is this true?

I agree

It sounds like you're planning on what's called "non-continuous support" as opposed to using cable trays or conduit for the comunications cables. According to standard TIA/EIA-569, "Commercial Building Standard for Telecommunications Pathways and Spaces," communications cables must be supported in one of three ways: by cantilever brackets from a wall, trapeze or individual rod supports from the ceiling, or directly from the floor. In addition, "rods or wires that are currently employed for other functions (e.g. suspended ceiling grid support) shall not be utilized as attachment points for non-continuous support.

If you're planning a new installation or retrofit I suggest that you hire a consultant and/or installer who is RCDD-qualified (Registered Communications Distribition Designer) by the Buildings Industry Consulting Service International (BICSI). This ensures that proper methods are followed.

e... nicely stated!
I can't quote any specific code on this one but I would add that other rules such as laying cables on suspended ceilings and the like will be flagged by a Building Sub Code Official...
Aside from the code just attempting good workman like installation practices would argue against the fast and easy solutions like ty-raps and conduits.